The need to power portable electronics equipment, communications gear, medical devices and other equipment in remote field service has been on the rise in recent years, increasing the demand for efficient, mobile power systems. These applications require power sources that provide both high power and energy density, while also requiring minimal size and weight, and cost.
To date, batteries have been the principle means for supplying portable sources of power. However, due to the time required for recharging, batteries have proven inconvenient for continuous use applications. Moreover, portable batteries are generally limited to power production in the range of several milliwatts to a few watts and thus cannot address the need for significant levels of mobile, lightweight power production.
Small generators powered by internal combustion engines, whether gasoline- or diesel-fueled have also been used. However, field situations, particularly in military applications, can demand multi-fuel capabilities. Gas turbine powered generators possess multi-fuel capability and can produce power at high efficiencies. While relatively low-efficiency micro-turbines exist, the majority of gas turbine engines are large and not well suited to field applications requiring high mobility. While conventional heat engines powered by high energy density liquid fuels offer advantages with respect to size, thermodynamic scaling and cost considerations have tended to favor larger power plants.
In view of these factors, a void exists with regard to power systems in the size range of 500 to 5000 watts. Moreover, in order to take advantage of mid-distillate high energy density liquid fuels, improved systems for managing temperature and reducing crankcase oil dilution in a spark-ignited internal combustion engine are needed.
Therefore, what is needed is a portable power system having multi-fuel capabilities that takes advantage of high energy density liquid fuels, including mid-distillates, while minimizing crankcase oil dilution.